New Crow Sam Gibson was so blindsided by his trade to Adelaide that he didn't even know he was eligible after the Kangaroos delisted him.

The man with the competition's longest active streak of games at 130 faced a life without football when he was a casualty of North Melbourne's aggressive rebuilding strategy.

Gibson, 31, thought the only hope of continuing his late-starting AFL career was as a delisted free agent, but he technically remained under contract until October 31.

A call from Crows coach Don Pyke on Tuesday put the wheels in motion before they handed pick 91 to the Roos to secure Gibson on a one-year deal.

"To be honest, I didn't even think a trade was an option even two days ago, but it all happened really quickly, as stuff often does," Gibson said.

"I got contacted by Don on maybe Tuesday and it all just happened really quickly and thankfully something got done now, and my mind's been put at ease.

"To be fair, there are a lot of rules and regulations and often players aren't across that sort of stuff."

Gibson averaged 22.1 disposals, 4.5 score involvements and 3.2 tackles this year, and finished seventh in North's best and fairest after placing third in 2016.

He clearly caught the Crows' attention with his round seven defensive job on Rory Sloane that saw other clubs follow suit with close tags on the midfield star.

Gibson told AFL.com.au from Bali last week he found it "hard to fathom that you can be in the best 22 for 130 weeks, finish sixth in the best and fairest and not get a contract".

At the same time, he understood the Roos had tough calls to make.

"It was a decision that I didn't agree with for my own reasons, but I'm not a list manager and I'm not planning for the future," Gibson said.

"I'm planning for what I'm doing. So, I understand it as best I can and I have no hard feelings. North Melbourne gave me an opportunity when no one else would.

"They gave me six wonderful years and I have really, really good relationships with both players and staff, and they're memories I'll cherish forever."

Gibson, who was on Hawthorn’s rookie list in 2007, is looking forward to the challenge of breaking into the Adelaide line-up from round one next year.

"I certainly hope so, but the assurances I've had from Don is that it's a team that's based around hard work and sacrifice and playing your role – and that's something I've always prided myself on doing," he said.

"But I'm under no illusions that it's going to be really hard work.

"I'm going to have to move states, find my feet again, work my butt off and hopefully if I have a good pre-season and put the right foot forward, there will be an opportunity there for me."